Why is the symbol for the EU a circle of stars?

A symbol of unity in Europe and no way having anything to do with the number of member countries, the symbol for the European Union is a circle of stars on an azure blue background. Why is it a circle of stars?
In the bible, especially in the Jehovah Witness' favourite book, the Book of Revelation, one of the women of the Apocalypse has a crown of twelve stars. Supposedly, this woman is the Virgin Mary which is why she is often depicted with such starry crown.
This imagery inspired Arsène Heitz to design a flag that would later be adopted by the Council of Europe in Paris, France on 13 December 1955. Since then, the circle of stars has been seen on flagpoles of EU nations and in recent years on Euro coins.